In a typical land mobile radio system, such as a mobile cellular telephone system or personal communications network (PCN), a plurality of cells are defined which make up the system. Each cell is a geographically defined area wherein communications are handled by a land mobile radio base site (cell site) for mobile units operating within the boundaries of the cell. Although these cells are often represented as hexagons in cell design schemes, in reality, due to terrain and the presence of buildings and other structures, the actual boundary of a cell may have an irregular shape.
As is well known in the art, cell layouts are typically characterized by a frequency reuse pattern where a number of different frequency sets are defined. Each cell uses a particular frequency set, and the cell layout is designed to provide the maximum separation between cells using the same frequency set so as to minimize interference.
It is generally required, depending on the location of the cell site within a cell, that the cell site antennas provide coverage for communications over 360.degree. of azimuth in order to effectively cover the corresponding geographic area. In existing base sites, either omni-directional antennas or panel antennas are used to provide the 360.degree. of azimuth. If panel antennas are used, the 360.degree. of azimuth is divided into a number of smaller sectors, such as three sectors, with each sector provided with a pair of antennas each having a beamwidth of 120.degree..
Usage monitoring in a base site is important to the operator of a base site because it provides important information regarding the utilization of the resources at the base site during communications between mobil radios and the base site (call traffic or traffic). In base sites such as those described above using omni-directional antennas or panel antennas usage monitoring is typically performed on a per-channel basis. More particularly, the operator of the base site is typically provided with usage information indicative of the amount (duration) that each channel is used during a specified time period. Therefore, the operator of the base site is provided information regarding the usage of each radio channel unit in the base site. However, in such systems the operator is unable to monitor usage based upon the physical location of a mobile unit with respect to the base site.
Recently, base sites have been developed having a sectorized antenna configuration wherein a large number of directional antennas or antennas having a large number of directional beams are employed. In such systems, it would be desirable to provide more useful information to the operator of the base site. In particular, it would be desirable to provide the base site operator with information indicative of the azimuthal distribution of communications with respect to the base site.